Edwards RV12, Инструкция по эксплуатации, Страница: 37 / 64

5.3 Start-up procedure
WARNING:
Ensure that the system design does not allow the exhaust pipeline to be blocked.
If the oil is contaminated, or if the pump temperature is below 12 °C, or if the electrical
supply voltage is more than 10% below the lowest voltage specified on the voltage
indicator ( Figure: Motor voltage configuration: single-phase pumps , item 3), the pump
may operate at a reduced speed for a few minutes. On single-phase pumps, if the pump
continues to operate at reduced speed, the motor thermal overload device will open
and stop the pump. When the motor has cooled, the thermal overload device will reset
automatically and the pump will restart.
1. Check that the pump oil-level is between the MAX and MIN marks on the bezel of
the oil-level sight-glass; if it is not, refer to Check the oil-level on page 41.
2. Turn the mode selector fully clockwise to select High Vacuum mode
S
or fully
anticlockwise to select High Throughput mode
S
, as required (refer to Check the
oil-level on page 41).
3. Turn the gas-ballast control to position ‘0’, ‘I’ or ‘II’, as required (refer to Gas-ballast
control on page 36).
4. Switch on the electrical supply to the pump; on single-phase pumps, use the on/off
switch.
5. In order to achieve ultimate vacuum, to pump condensable vapours or to
decontaminate the pump oil, refer to the procedures in To achieve ultimate
vacuum on page 37, To pump condensable vapours on page 38 and To
decontaminate the oil on page 38 respectively. Otherwise, open the vacuum
system isolation-valve.
5.4 To achieve ultimate vacuum
If the pump does not achieve the performance specified in Performance on page 13,
make sure that this is not due to the system design before contacting us or the supplier
for advice. In particular, the vapour pressure of all materials used in the vacuum system
(including pump oil, see below) must be much lower than the specified ultimate vacuum
of the pump. Refer to The pump has failed to achieve the specified performance (has
failed to reach ultimate vacuum) on page 47 for a list of possible causes for failure to
achieve the specified performance. Note however that the most common causes are:
▪ The pressure measurement technique or gauge head is unsuitable or the gauge
head is faulty.
▪ If an oil other than the recommended oil has been used, and the vapour pressure
of the oil is higher than the specified ultimate vacuum of the pump.
Use the following procedure to achieve ultimate vacuum:
1. Isolate the RV pump from the vacuum system.
2. Turn the mode selector to select High Throughput mode
S
, set the gas-ballast
control to low flow (position ‘I’) and operate the pump for at least 1 hour (or
overnight) to thoroughly purge the oil of contaminants.
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A65201880_AA - Operation